The proposed research focuses on the epidemiology of disordered sleep among adolescents. There are two primary objectives. The first is descriptive, focusing on prevalence, incidence, natural history and phenomenology. The second is analytic, in which there are two foci. The first analytic focus is to examine the role of risk and protective factors in the etiology of disordered sleep. The second analytic focus is to examine the consequences of disordered sleep on subsequent functioning of adolescents. We also will examine the role of ethnicity as a risk or protective factor among adolescents. We are interested in whether there is a unique risk for sleep disorders associated with ethnic culture above and beyond the risk attributable to other factors, and if so, what it is about ethnic culture that enhances or reduces risk. The proposed study involves a three-wave, prospective design. In addition to disordered sleep, other mental health outcomes of interest are DSM-lV anxiety and affective disorders, disruptive, and substance abuse disorders. Data will be collected from a cohort of 2,250 European, Latino, and African American adolescents aged 15-21 years of age residing in the Houston urban area. These youths were surveyed initially as part of the Teen Health 2000 study when they were 11-17 years of age (n=4200) and again a year later, when they were 12-18 years of age (n=3,150). Data on sleep will be collected using three strategies. First, a Sleep-Wake Diary will elicit information on sleep-wake patterns for the previous 24 hours. Second, a DSM-lV diagnostic module will elicit data permitting diagnosis of DSM-lV sleep disorders. Third, we will collect data using the same sleep module used in the first two-waves. Questions focus on amount of sleep, perceived need for sleep, bedtime and wake times, use of hypnotics, perceived quality of sleep, and a list of 13 symptoms of problematic sleep experienced during the past four weeks and frequency of occurrence. We will estimate point prevalence, incidence, natural history, and comorbidity with psychiatric disorders: affective disorders (such as major depression, dysthymia and mania/hypomania), anxiety disorders (such as generalized anxiety, posttraumatic stress disorder and panic), and behavioral disorders (conduct, oppositional defiant and attention-deficit/hyperactivity disorder), alcohol abuse and other substance abuse. Ethnicity is assessed using a multifactorial strategy, including generational status, language use, salience of ethnicity, ethnic identity, and discrimination. Social placement factors include age, gender, ethnic status, and marital/parental status. Stressors include discrimination, acculturative stress, indicators of stress exposure (acute, chronic, and traumatic life events), poor health, financial strain, poor school performance, and stressful neighborhood context Personal and social resources include factors such as social support, relations with parents, socioeconomic status, coping, self-esteem and mastery. Data will be collected using laptop computers and audio-computer assisted self-interview (ACASI) technology.